The current study aims to study the optimal fermentation conditions for producing microbial bioactive compounds. The microwave parameters consist on 2450 MHz, and 500-watt for 20, 30, and 40 seconds. The solubility of solvents was tested for the extraction of antioxidant compounds from fermented rice (Koji) by A. flavus, Ethyl acetate was the best solvent used for extraction purposes. Antioxidant properties were differentiated by blocking the oxidation of the linoleic acid with an inhibition rate of 73.13% at a concentration of 200 mg/mL, in addition to increasing its effectiveness for free radical extraction and reduction strength by increasing concentrations gradually. The bond ability to irons was lower compared to the EDTA-2Na, in addition to the obtained total content corresponding to phenolic compounds in the ethyl acetate extract of fermented rice (Koji) by A. flavus was 232.11 mg, on the basis of galic acid/mg. The stability of the antioxidant compounds of the ethyl acetate extract of fermented rice (Koji) by A. flavus was also studied; showing stability under neutral conditions, as well as at high temperatures (185 °C during two hours). However, no stability was obtained under acidic and alkaline conditions.

The study included preparation of aqueous (As) and alcoholic (ethanolic Es , methanolic Ms ) and oil extracts (Os) of Zahdi date seeds (Zs)(Phoenix dactylifera) . Chemical content of date seed was studied and the total content of phenols and flavonoids were estimated for prepared extract. Bioactive compounds of this extract was identification by Gas Chromatography Mass Spectrometer GCl MS. Antioxidant activity , reducing power, chelating of iron ions of extract was studied , then used the extract which gave highest antioxidant activity in beef patties with two concentrations 0.05% and 0.1% to test their efficiency in oxidative inhibition and prolonging the reservoir age of stored beef patties in refrigerated for 10days and following chemical indicators in Peroxide value(PV) , Thiobarbituric acid(TBA) in treated beef patties . Moisture , protein ,oil, ash and carbohydrate contents of Zs 9.36% , 4.87% , 8.56% , 1.34%, 75.87% respectively . All extracts containing many bioactive compounds that identification of GC-MS and differented in their percentage according to the type of extract. All extracts share with some bioactive compound as 1-(+)-Ascorbic acid 2,6-dihexadecanoate, gamma.sitosterol ,Octadecanoic 5-Methyl-2-ethylamino-2thiazoline, acid , Hexadecanoic acid and 2-hydroxy-1-(hydrixymethyl)ethylester . Alcoholic extracts (Es and Ms) exhibited the highest content of phenolic compound compared with As was 67.32mglml for Es , Ms was 65.32mglml While the total content of flavonoids for As 33.32mglml and Es 52.16 mglml , 46.16mglml for Ms , As and alcoholic extracts of Zs exhibited antioxidant activity was 88.70% for Es and 87.02% for Os , 85.22% for Ms , but As was the lowest 43.01% . The prepared extracts showed the higher reducing power was 2.63 and Chelating of iron ions 60.93 % and for Es , There was a significant decrease (P<0.05)in peroxide value and thiobarbituric acid in beef patties treated with ethanolic extracts compared with control.

The present study proposes microwave-assisted extraction as a sustainable technique for the biosynthesis of bioactive compounds from rice fermented with Aspergillus flavus (koji). First, fermentation conditions (i.e., pH from 3–12, five temperatures from 20–40 °C, and four culture-fermentation media viz. wheat, wheat bran, malt and rice) were optimized for producing microbial bioactive compounds. Microwave extraction was performed at 2450 MHz and 500 W for 20, 30, and 40 s with seven solvents (distilled water, ethyl acetate, hexane, ethanol, chloroform, diethyl ether, and methanol). The obtained results revealed that ethyl acetate is the most appropriate solvent for extraction. Effects of this ethyl acetate extract were compared with a commercial synthetic antioxidant. Antioxidant properties were enhanced by preventing the oxidation of the linoleic acid (C18H32O2) with an inhibition rate (antioxidant efficacy) of 73.13%. Notably, the ferrous ion binding ability was marginally lower when compared to the disodium salt of ethylenediaminetetraacetic acid (EDTA). Additionally, the obtained total content of phenolic compounds in the ethyl acetate extract of fermented rice (koji) by Aspergillus flavus was 232.11 mg based on gallic acid/mL. Antioxidant compounds in the ethyl acetate extract of fermented rice showed stability under neutral conditions, as well as at high temperatures reaching 185 °C during 2 h, but were unstable under acidic and alkaline conditions. The results demonstrate the efficacy of novel microwave-assisted extraction technique for accelerating antioxidant production during rice fermentation.